Page 3 of 5 FirstFirst 12345 LastLast
Results 21 to 30 of 46

Thread: openSUSE 13.1 have to restore Grub

  1. #21
    Join Date
    Aug 2010
    Location
    Chicago suburbs
    Posts
    13,308
    Blog Entries
    3

    Default Re: openSUSE 13.1 have to restore Grub

    Quote Originally Posted by hcvv View Post
    @mrmazda.

    Let me try to express what I understand from this.

    In the MBR there can be so called "generic boot code", which means that there can also be some specific boot code.

    I assume my situaton is that in the MBR there is now 15.1 specific boot code and that there should be generic boot code.

    For some reason the writing of this generic boot code (overwriting the 15.1 boot code) does not work.
    I was never sure whether that generic boot code is put back at later updates.

    You can put generic boot code there yourself, fairly easily.

    Code:
    cd /usr/share/syslinux
    cat mbr.bin > /dev/sda
    If you are squeamish about the use of "cat" there, you could alternatively use (from same directory)
    Code:
    dd if=mbr.bin of=/dev/sda bs=440 count=1
    However, the size of "mbr.bin" should be 440 bytes, so the "cat" does about the same thing.

    You can do that in 15.1. It's generic boot code, so it isn't important which version it comes from.

    Hmm, if we go back far enough, "syslinux" was not automatically installed. It is part of a 15.1 install, and I'm pretty sure that it was already part of a 13.1 install.

    Am I right that the crucial question is how we can force that?
    Doing it with YaST bootloader from the chrooted 13.1 seems to fail.
    I assume that in principle doing it from 15.1 must also be possible, after all it is the same MBR and the code is generic in both cases.
    (The 15.1 has the problem that KDE does not work, so again ncurses yast must do it).[/QUOTE]
    openSUSE Leap 15.1; KDE Plasma 5;
    testing Leap 15.2Alpha

  2. #22
    Join Date
    Jun 2008
    Location
    Netherlands
    Posts
    25,924

    Default Re: openSUSE 13.1 have to restore Grub

    That was something I was hoping for. A low level command to store generic boot code on the MBR.

    I did it from the chrooted 15.1. Result: No operating system found.

    So apart from that one action above where I wrote Generic boot code to MBR using YaST from 151.1 and that broke the MBR totaly, I never see any results from writing it. Go figure

    BTW, before I forget out of frustration, I realy appreciate all the help coming forward here.
    Henk van Velden

  3. #23
    Join Date
    Jun 2008
    Location
    Netherlands
    Posts
    25,924

    Default Re: openSUSE 13.1 have to restore Grub

    There is another option on the install DVD: Start a linux. Never used it before.
    It starts loading the DVDs kernel and then offers a menu with two possibilities to start, Yes, the 13.1 and the 15.1.
    After chsoosing one you can still choose another root disk (do not know why). In both cases (13.1 and 15.1) it then continues saying it can not boot it.

    I think I give up this MBR repairing and start a new 151. installation on the partitions I reserved for it. I hope that at least at the end I will be in the same situation as at the start of this thread (where the system is still unworkable, but at least I can then boot in 15.1).
    Henk van Velden

  4. #24
    Join Date
    Dec 2008
    Location
    FL, USA
    Posts
    2,058

    Default Re: openSUSE 13.1 have to restore Grub

    There remains to try the opposite of what I previously focused on. Instead, use chroot into 13.1 to configure Grub2 using YaST to boot from MBR instead of using generic MBR code to boot (either of 13.1's) Grub from from /.
    Reg. Linux User #211409 *** multibooting since 1992
    Primary: 42.3,TW,15.0 & 13.1 on Haswell w/ RAID
    Secondary: eComStation (OS/2)&42.3 on 965P/Radeon
    Tertiary: TW,15.0,42.3,Fedora,Debian,more on Kaby Lake,Q45,Q43,G41,G3X,965G,Cedar,Caicos,Oland,GT218&&&

  5. #25
    Join Date
    Aug 2010
    Location
    Chicago suburbs
    Posts
    13,308
    Blog Entries
    3

    Default Re: openSUSE 13.1 have to restore Grub

    Quote Originally Posted by hcvv View Post
    I did it from the chrooted 15.1. Result: No operating system found.
    Can you recheck whether the active flag is set on the partition you want to boot from?
    openSUSE Leap 15.1; KDE Plasma 5;
    testing Leap 15.2Alpha

  6. #26
    Join Date
    Jun 2008
    Location
    Netherlands
    Posts
    25,924

    Default Re: openSUSE 13.1 have to restore Grub

    OK, I chrooted in 13.1 removed the check from write generic boot code intoMBR and changed to Boot fro MBR.Also changed the timeout.

    No joy. Bios does not see a system at all.

    It looks as if that MBR area of the disk is read-only (without complaining).
    I am now going for the ultimate test: re-install 15.1 on sda1 Swap, sda3 / and sda6 /home

    Is there a preferred way to set things for Grub during install, taking into account that I still hope to get the 13.1 running?
    Henk van Velden

  7. #27
    Join Date
    Jun 2008
    Location
    Netherlands
    Posts
    25,924

    Default Re: openSUSE 13.1 have to restore Grub

    Quote Originally Posted by nrickert View Post
    Can you recheck whether the active flag is set on the partition you want to boot from?
    I did regular fdisk -l to check that. All the time the boot flag is on sda2 (the 13.1 root).
    When I understand mrmazda correct, that is only important as long as there is Generic boot code in the MBR.

    Is it correct that when there is other boot code in the MBR, the boot flag is unimportant?


    BTW, I can not prove it and will not try to repeat tha test, but IIRC even when I said to 15.1 yast to set the boot flag in it.s boot device (sda3), it never showed there.
    Henk van Velden

  8. #28
    Join Date
    Dec 2008
    Location
    FL, USA
    Posts
    2,058

    Default Re: openSUSE 13.1 have to restore Grub

    Wikipedia explains the boot flag well enough.
    Reg. Linux User #211409 *** multibooting since 1992
    Primary: 42.3,TW,15.0 & 13.1 on Haswell w/ RAID
    Secondary: eComStation (OS/2)&42.3 on 965P/Radeon
    Tertiary: TW,15.0,42.3,Fedora,Debian,more on Kaby Lake,Q45,Q43,G41,G3X,965G,Cedar,Caicos,Oland,GT218&&&

  9. #29
    Join Date
    Jun 2008
    Location
    Netherlands
    Posts
    25,924

    Default Re: openSUSE 13.1 have to restore Grub

    To keep you informed.

    I installed 15.1 on sda3(/) and sda6(/home).

    Grub menu now only shows two 15.1 entries. 15.1 is bootable. I did some adaptions from tty1. sddm would not work, switched to kdm (what I wanted to use anyhow). Did not use it, because my first priority is to get 13.1 running (else my will ... me).

    I am now going to use ncurses yast to set the Check for other OSes and see what happnes. Please keep your fingers crosses, I need it.
    Henk van Velden

  10. #30
    Join Date
    Jun 2008
    Location
    Netherlands
    Posts
    25,924

    Default Re: openSUSE 13.1 have to restore Grub

    Quote Originally Posted by mrmazda View Post
    Wikipedia explains the boot flag well enough.
    Thanks, will study it, I need it!
    Henk van Velden

Page 3 of 5 FirstFirst 12345 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •